Main components of the line profiles. The solid vertical line shows the source velocity, 11.4 km s^-1. The two velocity regimes of quiescent gas are illustrated by C¹⁸O and CH₃OH. The deep, narrow absorption feature in CO is due to emission in the reference beams, while the absorption in H₂O appears to be source-related. The broad blue component is represented by SO. The HF line traces foreground material in the foreground slab, at 9 km s^-1, with another contribution from the quiescent gas.